A Pilot Study to Evaluate 3′-Deoxy-3′-18F-Fluorothymidine PET for Initial and Early Response Imaging in Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma. Proliferation activity is considered an important prognostic marker. Immunohistochemical analysis from core biopsy or lymph node may not represent the proliferation rate. We investigated the in vivo proliferation marker 3'-deoxy-3'-F-18-fluorothymidine (F-18-FLT) to characterize MCL. Methods: Eight untreated MCL patients were recruited prospectively. F-18-FLT PET/CT was performed 45 min after injection of F-18-FLT. F-18-FDG PET/CT served as reference. Mean F-18-FLT standardized uptake values were assessed per lesion and compared with respective F-18-FDG uptake. Correlation of mean F-18-FLT and F-18-FDG uptake in the hottest lesion to Ki67 immunostaining was performed. Five patients underwent repetitive early F-18-FLT PET. Results: All lymphoma lesions identified by F-18-FDG PET/CT showed increased F-18-FLT uptake. Semiquantitative analysis revealed a high mean F-18-FLT standardized uptake value of 9.9 (range, 5.5-15.9). Mean F-18-FLT uptake and Ki67 expressions showed a strong positive correlation. Conclusion: PET using F-18-FLT as a biomarker for proliferative activity showed a high sensitivity for MCL. F-18-FLT uptake shows a correlation with proliferation. Our results warrant further analysis of F-18-FLT PET in MCL.